This adds a regresson test case for the revert reason of:
https://crrev.com/c/1906378

The test data is tidied up by keeping the different fake d8s in
separate build directories like it would be in production.

A new test simulates an architecture difference and ensures we
pass the architecture mocks in all runs.

No-Try: true
Bug: chromium:1023091
Change-Id: Ic33c426ba8eb9c4b6b0fbb66d43c0859dc2edfcd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1918248
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65140}